1. Field of the Invention
The present invention relates to a production apparatus of hypochlorite solution in which acid water and alkaline water are produced by electrolysis of chloride solution such as sodium chloride solution, potassium chloride solution or the like and mixed to produce hypochlorite solution.
2. Discussion of the Prior Art
Disclosed in Japanese Patent Publication No. 4-42077 is a production apparatus of this kind which includes an electrolytic cell having a housing the interior of which is subdivided by a partition membrane to form anode and cathode chambers, and positive and negative electrodes respectively disposed within the anode and cathode chambers and opposed to each other through the partition membrane. In the electrolytic cell, the positive and negative electrodes are applied with DC voltage to effect electrolysis of chloride solution supplied into both the anode and cathode chambers, and acid water and alkaline water produced by electrolysis of the chloride solution respectively in the anode and cathode chambers are mixed to produce hypochlorite solution.
In the electrolytic cell, the chloride solution supplied into the cathode chamber is uselessly consumed for production of the hypochlorite solution, resulting in an increase of the production cost of hypochlorite solution.
It is, therefore, a primary object of the present invention to provide a production apparatus of hypochlorite solution capable of producing the hypochlorite solution at a low cost without useless consumption of the chloride solution.
According to the present invention, the object is attained by providing a production apparatus of hypochlorite solution which includes an electrolytic cell having a housing the interior of which is subdivided by a partition membrane to form anode and cathode chambers, and positive and negative electrodes respectively disposed within the anode and cathode chambers and opposed to each other through the partition membrane, wherein the positive and negative electrodes are applied with DC voltage to effect electrolysis of chloride solution supplied into both the anode and cathode chambers, wherein acid water and alkaline water produced by electrolysis of the chloride solution respectively in the anode and cathode chambers are mixed to produce hypochlorite solution, and wherein the anode chamber of the electrolytic cell is supplied with chloride solution through a supply conduit connected thereto, while the cathode chamber of the electrolytic cell is supplied with city service water through a supply conduit connected thereto.
As in the production apparatus of hypochlorite solution, the cathode chamber R2 is supplied with the city service water for production of hypochlorite solution in the electrolytic cell, the consumption amount of salt for preparation of the chloride solution can be reduced less than that in the conventional apparatus in which the chloride solution is supplied into both the anode and cathode chambers. This is useful to reduce the production cost of hypochlorite solution. In the case that the anode chamber is supplied with chloride solution of high concentration, a conductive degree of ion can be increased, and the voltage between the electrodes can be lowered.
In a practical embodiment of the present invention, it is preferable that flow restriction means is provided in the anode chamber to restrict an amount of the chloride solution supplied into the anode chamber. In such an embodiment, an amount of non-electrolyzed chloride solution can be decreased to enhance the electrolysis efficiency of the chloride solution.
It is also preferable that a discharge conduit is connected to the cathode chamber of the electrolytic cell to discharge alkaline water from the cathode chamber therethrough and that flow quantity control means is provided on the partition membrane to adjust an amount of the alkaline water flowing into the anode chamber from the cathode chamber therethrough. In such an embodiment, the mixture ratio of acid water and alkaline water produced respectively in the anode chamber and cathode chamber can be adjusted by operation of the flow quantity control means to adjust the concentration and pH of hypochlorite solution.
Alternatively, in a practical embodiment of the present invention, a discharge conduit is connected to the cathode chamber of the electrolytic cell to discharge therethrough alkaline water from the cathode chamber, a flow quantity control valve is disposed within the discharge conduit to adjust an amount of alkaline water discharged from the cathode chamber through the discharge conduit, and a check valve is provided on the partition membrane to interrupt the flow of alkaline water from the cathode chamber into the anode chamber. In such an embodiment, the amount of alkaline water discharged from the cathode chamber through the discharge conduit can be adjusted by the flow quantity control valve so that the flow amount of alkaline water from the cathode chamber into the anode chamber is controlled to adjust the mixture ratio of alkaline water and acid water thereby to adjust the concentration and pH of the hypochlorite solution in desired values. In addition, the flow of acid water from the anode chamber into the cathode chamber is interrupted by the check valve to restrain deterioration of the negative electrode in the cathode chamber caused by reaction with hydrogen ion contained in the acid water.